Rising temperatures signal problems for honeybees

Posted Nov 29, 2014 by Tim Sandle
A bee parasite, normally associated with more exotic climates is threatening British bees. A new research model indicates that a rare gut parasite could cause increasing damage to U.K. bees as the climate warms.
Photo of a Wild Honeybee
Photo of a Wild Honeybee
Bees around the world face a considerable number of hazards and, in general, bee populations have been declining. The implication of declining bee populations around the globe has significant implications for the pollination plants and agriculture. For example, without bees to spread pollen from the male parts of plants to the female parts, fruit may not form. One of the causes is the over-use of pesticides, as Digital Journal has reported. Pesticides, or insecticides, aimed at reducing insect pests target the nervous system. Another factor is linked to a parasite.
Researchers have been looking into pathogen growth in British honey bees that were infected with both an exotic parasite called Nosema ceranae and its original native relative, Nosema apis. Nosema ceranae is a small, unicellular parasite. The disease afflicts adult bees and depopulation occurs with consequent losses in honey production.
Nosema ceranae is common in Southern Europe but it has hitherto been rare in Northern Europe. The shift towards the southern European parasite is seen as linked to warming temperatures in the North.
Experiments have shown that although both parasites inhibit each other's growth, the exotic Nosema ceranae has a much greater harmful impact on the native Nosema apis. By putting the effects of competition and climate into a computer, the scientists were better able to predict the relative occurrence of both parasite species in nature.
The exotic parasite is a better competitor than its original close relative. This is potentially bad news for the bees since this parasite is more dangerous and can potentially kill a large number of bees.
The study was carried out at Queen's University Belfast (Northern Ireland.) The findings have been published in the journal Proceedings of the Royal Society B. The paper is titled “Interspecific competition in honeybee intracellular gut parasites is asymmetric and favours the spread of an emerging infectious disease.”